Texture baking turns part of my object black
I know, 9 months late. I'm new to blender, but I figured this one out. If you have gloss in your material, you have to make a separate gloss map. The color is there. Save the diffuse map first, then make the glossy with a new texture map (save that), and finish by reloading the diffuse map. You now have 2 maps, plug them in where appropriate, and all should be fine.